An updated sediment source areas inventory in the Rio Cordon catchment (Dolomites)

Abstract

This study presents an inventory of sediment source areas updated to 2016 of the Rio Cordon catchment, a small headwater basin located in the Eastern Italian Alps. The aim of the 2016 inventory was to update an old sediment source areas dataset dating back to 2006, built using LiDAR-derived geomorphometric parameters interpretation and field survey, in order to evaluate the geomorphic changes occurred in the last 10 years in the catchment. The new inventory was realized by means of an extensive field survey campaign conducted with a mobile GIS mounted on a rugged notebook integrating a GPS receiver. Pictures of individual or collective sediment source areas were also acquired in order to integrate the GIS dataset and to better define their current status of activity. The images were also used for a comparison with the images acquired in 2006 to identify the evolution or stabilization of each sediment source area. The identification and delimitation of large and/or unreachable areas was carried out in the office by interpreting aerial photo images (Bing satellite images and Web Map Services for AGEA 2009-2012 aerial photographs, compared with the old LiDAR-derived high resolution images used for the 2006 sediment source inventory). The comparison with the previous inventory shows that several old sediment sources resulted totally stabilized indicating a general decrease of erosion processes in the catchment. In contrast, some new sediment source areas were identified. They were mainly related to a very recent rock fall that took place in July 2016 in the Lastoni di Formin group and many new shallow landslides were found in the upper part of small Rio Cordon tributary where a small debris flow event occurred in 2012. © Società Geologica Italiana, Roma 2017

Predicting sediment connectivity in a mountain basin: A quantitative analysis of the index of connectivity

“…From 1994 to 2006, 127 more sources were identified, increasing the total number up to 419 with a total surface of about 648 554 m 2 (Cavalli et al, 2016). After 10 years, the catchment was again surveyed and a new inventory was obtained supported by a dataset of photos (Ferrato et al, 2017). The 2016 inventory presented 420 sediment sources and a total surface of about 652 100 m 2 .…”

Coupling Climate Conditions, Sediment Sources and Sediment Transport in an Alpine Basin

“…Overall, these areas cover roughly 13% of the basin (Ferrato et al . ). Because of the presence of a low‐gradient belt located at approximately 2,200 m.a.s.l., the upstream sources provide a minor contribution to the sediment export (Dalla Fontana & Marchi ).…”

“…In relation to the sediment cascade, the basin exhibits a wide presence of sediment sources, which consist mainly of debris flow channels and flow deposits, landslides and talus slopes. Overall, these areas cover roughly 13% of the basin (Ferrato et al 2017). Because of the presence of a low-gradient belt located at approximately 2,200 m.a.s.l., the upstream sources provide a minor contribution to the sediment export (Dalla Fontana & Marchi 2003).…”

“…Further details on the Rio Cordon inventories and on the methodology used can be found in Cavalli et al (2016) and Ferrato et al (2017).…”

Hydrological, geomorphic and sedimentological responses of an alpine basin to a severe weather event (Vaia storm)

“…Along the basin, the Rio Cordon is interrupted by a waterfall, which represents a topographic knickpoint that conventionally divides the whole basin into the upper part (upper plateau) and lower part (Rainato et al, 2018b). In 2016, 420 sediment source areas were detected throughout the basin, classified in debris flow channel/deposit, erosional area, stream bank erosion, landslide, rockfall deposit and active talus (Ferrato et al, 2017). From the sources, the sediment can be transported downstream and eventually deposited at the outlet (1763 m a.s.l.…”